Intel, Freescale, and Marvell are being targeted in a lawsuit claiming they've infringed on a 1996 patent involving on-chip power management. The complaint by “Power Management Systems LLC” reportedly names Intel's Atom Z6xx, Freescale's i.MX515, and Marvell's PXA940 as relevant products, adding that the alleged infringement is not necessarily limited to these processors.

According to reports by EETimes, Thinq, and Tom's Hardware, Frisco, Texas-based Power Management Systems filed a complaint earlier this week in the U.S. District Court in Delaware. We couldn't find the relevant document on the Court's opaque website, but it's said to cite U.S. Patent No. 5,504,909, titled "Power Management Apparatus Co-located on the Same Integrated Circuit as the Functional Unit that it Manages."

The patent was filed in January 1994 by Dublin, California-based Electronics Products Company, granted in April of 1996, and apparently later sold to Power Management Systems. Its abstract reads as follows:

"A power management apparatus that controls the use of power within an integrated circuit. A first embodiment gates integrated circuit power on or off concurrently with switches inserted between the co-resident functional circuit I/O nets and the integrated circuit I/O pads. A second embodiment instantiates the power management apparatus on an integrated circuit by itself for connection to external integrated circuits. Buffering or sequencing is provided for both embodiments."

The patent further noted, "The invention is particularly useful, though not exclusively applicable, to any electronic device that can employ more than one rate of power consumption, and where control of the total power used by the electronic device is desirable."

As such, the patent would appear to relate to technologies such as Intel's SpeedStep technology and AMD's PowerNow, among others. Thinq author Gareth Halfacree adds that "Even ACPI [link], which includes in-built power management capabilities, wasn't released until December 1996.

Power Management Systems' complaint reportedly names Intel's Atom Z6xx, Freescale's i.MX515, and Marvell's PXA940 as infringing products. There was no information on why these three were called out — since on-chip power management is a feature of most of the chipmakers' other products too — nor why the suit was filed at this late date.

Power Management Systems is asking for damages, attorney's fees, filing costs, and a trial before jury for "such other and further relief as the Court deems just and proper."

Like other Texas-based "patent trolls" — go here for a transcript of the recent expose by National Public Radio's This American Life program — the company presumably hopes Intel, Freescale, and Marvell will choose to settle out of court.

Jonathan Angel can be reached at [email protected] and followed at www.twitter.com/gadgetsense.

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